The Google Cloud database migration path follows a "like-for-like" managed service strategy. Cloud SQL is the recommended destination for MySQL and SQL Server workloads that do not require the massive horizontal scale of Spanner, fitting Cymbal’s "Technical Stack Modernization" goals. Memorystore is the managed service for Redis, and Firestore is the native NoSQL replacement for MongoDB.

For the image storage requirement, Cloud Storage Coldline is the mathematically correct choice for data accessed "less and less frequently" with a retention period exceeding 90 days. According to Cloud Storage documentation, Coldline is specifically designed for data accessed at most once a quarter (90 days). Using Object Lifecycle Management to move images from Standard to Coldline allows Cymbal to "reduce costs" while keeping images "immediately accessible" (unlike Archive storage, which may have different trade-offs). Option C is less optimal because Nearline is intended for 30-day access patterns; given the images stay for 90+ days and usage drops significantly, the deeper savings of Coldline are preferred. Option A is over-engineered (Spanner for all) and expensive, while Option B contradicts the requirement to "reduce costs" by increasing operational overhead